FFmpeg
channel_layout.h
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1 /*
2  * Copyright (c) 2006 Michael Niedermayer <michaelni@gmx.at>
3  * Copyright (c) 2008 Peter Ross
4  *
5  * This file is part of FFmpeg.
6  *
7  * FFmpeg is free software; you can redistribute it and/or
8  * modify it under the terms of the GNU Lesser General Public
9  * License as published by the Free Software Foundation; either
10  * version 2.1 of the License, or (at your option) any later version.
11  *
12  * FFmpeg is distributed in the hope that it will be useful,
13  * but WITHOUT ANY WARRANTY; without even the implied warranty of
14  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
15  * Lesser General Public License for more details.
16  *
17  * You should have received a copy of the GNU Lesser General Public
18  * License along with FFmpeg; if not, write to the Free Software
19  * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA
20  */
21 
22 #ifndef AVUTIL_CHANNEL_LAYOUT_H
23 #define AVUTIL_CHANNEL_LAYOUT_H
24 
25 #include <stdint.h>
26 #include <stdlib.h>
27 
28 #include "version.h"
29 #include "attributes.h"
30 
31 /**
32  * @file
33  * audio channel layout utility functions
34  */
35 
36 /**
37  * @addtogroup lavu_audio
38  * @{
39  */
40 
41 enum AVChannel {
42  ///< Invalid channel index
62  /** Stereo downmix. */
64  /** See above. */
76 
77  /** Channel is empty can be safely skipped. */
78  AV_CHAN_UNUSED = 0x200,
79 
80  /** Channel contains data, but its position is unknown. */
81  AV_CHAN_UNKNOWN = 0x300,
82 
83  /**
84  * Range of channels between AV_CHAN_AMBISONIC_BASE and
85  * AV_CHAN_AMBISONIC_END represent Ambisonic components using the ACN system.
86  *
87  * Given a channel id <i> between AV_CHAN_AMBISONIC_BASE and
88  * AV_CHAN_AMBISONIC_END (inclusive), the ACN index of the channel <n> is
89  * <n> = <i> - AV_CHAN_AMBISONIC_BASE.
90  *
91  * @note these values are only used for AV_CHANNEL_ORDER_CUSTOM channel
92  * orderings, the AV_CHANNEL_ORDER_AMBISONIC ordering orders the channels
93  * implicitly by their position in the stream.
94  */
96  // leave space for 1024 ids, which correspond to maximum order-32 harmonics,
97  // which should be enough for the foreseeable use cases
99 };
100 
102  /**
103  * Only the channel count is specified, without any further information
104  * about the channel order.
105  */
107  /**
108  * The native channel order, i.e. the channels are in the same order in
109  * which they are defined in the AVChannel enum. This supports up to 63
110  * different channels.
111  */
113  /**
114  * The channel order does not correspond to any other predefined order and
115  * is stored as an explicit map. For example, this could be used to support
116  * layouts with 64 or more channels, or with empty/skipped (AV_CHAN_SILENCE)
117  * channels at arbitrary positions.
118  */
120  /**
121  * The audio is represented as the decomposition of the sound field into
122  * spherical harmonics. Each channel corresponds to a single expansion
123  * component. Channels are ordered according to ACN (Ambisonic Channel
124  * Number).
125  *
126  * The channel with the index n in the stream contains the spherical
127  * harmonic of degree l and order m given by
128  * @code{.unparsed}
129  * l = floor(sqrt(n)),
130  * m = n - l * (l + 1).
131  * @endcode
132  *
133  * Conversely given a spherical harmonic of degree l and order m, the
134  * corresponding channel index n is given by
135  * @code{.unparsed}
136  * n = l * (l + 1) + m.
137  * @endcode
138  *
139  * Normalization is assumed to be SN3D (Schmidt Semi-Normalization)
140  * as defined in AmbiX format $ 2.1.
141  */
143 };
144 
145 
146 /**
147  * @defgroup channel_masks Audio channel masks
148  *
149  * A channel layout is a 64-bits integer with a bit set for every channel.
150  * The number of bits set must be equal to the number of channels.
151  * The value 0 means that the channel layout is not known.
152  * @note this data structure is not powerful enough to handle channels
153  * combinations that have the same channel multiple times, such as
154  * dual-mono.
155  *
156  * @{
157  */
158 #define AV_CH_FRONT_LEFT (1ULL << AV_CHAN_FRONT_LEFT )
159 #define AV_CH_FRONT_RIGHT (1ULL << AV_CHAN_FRONT_RIGHT )
160 #define AV_CH_FRONT_CENTER (1ULL << AV_CHAN_FRONT_CENTER )
161 #define AV_CH_LOW_FREQUENCY (1ULL << AV_CHAN_LOW_FREQUENCY )
162 #define AV_CH_BACK_LEFT (1ULL << AV_CHAN_BACK_LEFT )
163 #define AV_CH_BACK_RIGHT (1ULL << AV_CHAN_BACK_RIGHT )
164 #define AV_CH_FRONT_LEFT_OF_CENTER (1ULL << AV_CHAN_FRONT_LEFT_OF_CENTER )
165 #define AV_CH_FRONT_RIGHT_OF_CENTER (1ULL << AV_CHAN_FRONT_RIGHT_OF_CENTER)
166 #define AV_CH_BACK_CENTER (1ULL << AV_CHAN_BACK_CENTER )
167 #define AV_CH_SIDE_LEFT (1ULL << AV_CHAN_SIDE_LEFT )
168 #define AV_CH_SIDE_RIGHT (1ULL << AV_CHAN_SIDE_RIGHT )
169 #define AV_CH_TOP_CENTER (1ULL << AV_CHAN_TOP_CENTER )
170 #define AV_CH_TOP_FRONT_LEFT (1ULL << AV_CHAN_TOP_FRONT_LEFT )
171 #define AV_CH_TOP_FRONT_CENTER (1ULL << AV_CHAN_TOP_FRONT_CENTER )
172 #define AV_CH_TOP_FRONT_RIGHT (1ULL << AV_CHAN_TOP_FRONT_RIGHT )
173 #define AV_CH_TOP_BACK_LEFT (1ULL << AV_CHAN_TOP_BACK_LEFT )
174 #define AV_CH_TOP_BACK_CENTER (1ULL << AV_CHAN_TOP_BACK_CENTER )
175 #define AV_CH_TOP_BACK_RIGHT (1ULL << AV_CHAN_TOP_BACK_RIGHT )
176 #define AV_CH_STEREO_LEFT (1ULL << AV_CHAN_STEREO_LEFT )
177 #define AV_CH_STEREO_RIGHT (1ULL << AV_CHAN_STEREO_RIGHT )
178 #define AV_CH_WIDE_LEFT (1ULL << AV_CHAN_WIDE_LEFT )
179 #define AV_CH_WIDE_RIGHT (1ULL << AV_CHAN_WIDE_RIGHT )
180 #define AV_CH_SURROUND_DIRECT_LEFT (1ULL << AV_CHAN_SURROUND_DIRECT_LEFT )
181 #define AV_CH_SURROUND_DIRECT_RIGHT (1ULL << AV_CHAN_SURROUND_DIRECT_RIGHT)
182 #define AV_CH_LOW_FREQUENCY_2 (1ULL << AV_CHAN_LOW_FREQUENCY_2 )
183 #define AV_CH_TOP_SIDE_LEFT (1ULL << AV_CHAN_TOP_SIDE_LEFT )
184 #define AV_CH_TOP_SIDE_RIGHT (1ULL << AV_CHAN_TOP_SIDE_RIGHT )
185 #define AV_CH_BOTTOM_FRONT_CENTER (1ULL << AV_CHAN_BOTTOM_FRONT_CENTER )
186 #define AV_CH_BOTTOM_FRONT_LEFT (1ULL << AV_CHAN_BOTTOM_FRONT_LEFT )
187 #define AV_CH_BOTTOM_FRONT_RIGHT (1ULL << AV_CHAN_BOTTOM_FRONT_RIGHT )
188 
189 #if FF_API_OLD_CHANNEL_LAYOUT
190 /** Channel mask value used for AVCodecContext.request_channel_layout
191  to indicate that the user requests the channel order of the decoder output
192  to be the native codec channel order.
193  @deprecated channel order is now indicated in a special field in
194  AVChannelLayout
195  */
196 #define AV_CH_LAYOUT_NATIVE 0x8000000000000000ULL
197 #endif
198 
199 /**
200  * @}
201  * @defgroup channel_mask_c Audio channel layouts
202  * @{
203  * */
204 #define AV_CH_LAYOUT_MONO (AV_CH_FRONT_CENTER)
205 #define AV_CH_LAYOUT_STEREO (AV_CH_FRONT_LEFT|AV_CH_FRONT_RIGHT)
206 #define AV_CH_LAYOUT_2POINT1 (AV_CH_LAYOUT_STEREO|AV_CH_LOW_FREQUENCY)
207 #define AV_CH_LAYOUT_2_1 (AV_CH_LAYOUT_STEREO|AV_CH_BACK_CENTER)
208 #define AV_CH_LAYOUT_SURROUND (AV_CH_LAYOUT_STEREO|AV_CH_FRONT_CENTER)
209 #define AV_CH_LAYOUT_3POINT1 (AV_CH_LAYOUT_SURROUND|AV_CH_LOW_FREQUENCY)
210 #define AV_CH_LAYOUT_4POINT0 (AV_CH_LAYOUT_SURROUND|AV_CH_BACK_CENTER)
211 #define AV_CH_LAYOUT_4POINT1 (AV_CH_LAYOUT_4POINT0|AV_CH_LOW_FREQUENCY)
212 #define AV_CH_LAYOUT_2_2 (AV_CH_LAYOUT_STEREO|AV_CH_SIDE_LEFT|AV_CH_SIDE_RIGHT)
213 #define AV_CH_LAYOUT_QUAD (AV_CH_LAYOUT_STEREO|AV_CH_BACK_LEFT|AV_CH_BACK_RIGHT)
214 #define AV_CH_LAYOUT_5POINT0 (AV_CH_LAYOUT_SURROUND|AV_CH_SIDE_LEFT|AV_CH_SIDE_RIGHT)
215 #define AV_CH_LAYOUT_5POINT1 (AV_CH_LAYOUT_5POINT0|AV_CH_LOW_FREQUENCY)
216 #define AV_CH_LAYOUT_5POINT0_BACK (AV_CH_LAYOUT_SURROUND|AV_CH_BACK_LEFT|AV_CH_BACK_RIGHT)
217 #define AV_CH_LAYOUT_5POINT1_BACK (AV_CH_LAYOUT_5POINT0_BACK|AV_CH_LOW_FREQUENCY)
218 #define AV_CH_LAYOUT_6POINT0 (AV_CH_LAYOUT_5POINT0|AV_CH_BACK_CENTER)
219 #define AV_CH_LAYOUT_6POINT0_FRONT (AV_CH_LAYOUT_2_2|AV_CH_FRONT_LEFT_OF_CENTER|AV_CH_FRONT_RIGHT_OF_CENTER)
220 #define AV_CH_LAYOUT_HEXAGONAL (AV_CH_LAYOUT_5POINT0_BACK|AV_CH_BACK_CENTER)
221 #define AV_CH_LAYOUT_6POINT1 (AV_CH_LAYOUT_5POINT1|AV_CH_BACK_CENTER)
222 #define AV_CH_LAYOUT_6POINT1_BACK (AV_CH_LAYOUT_5POINT1_BACK|AV_CH_BACK_CENTER)
223 #define AV_CH_LAYOUT_6POINT1_FRONT (AV_CH_LAYOUT_6POINT0_FRONT|AV_CH_LOW_FREQUENCY)
224 #define AV_CH_LAYOUT_7POINT0 (AV_CH_LAYOUT_5POINT0|AV_CH_BACK_LEFT|AV_CH_BACK_RIGHT)
225 #define AV_CH_LAYOUT_7POINT0_FRONT (AV_CH_LAYOUT_5POINT0|AV_CH_FRONT_LEFT_OF_CENTER|AV_CH_FRONT_RIGHT_OF_CENTER)
226 #define AV_CH_LAYOUT_7POINT1 (AV_CH_LAYOUT_5POINT1|AV_CH_BACK_LEFT|AV_CH_BACK_RIGHT)
227 #define AV_CH_LAYOUT_7POINT1_WIDE (AV_CH_LAYOUT_5POINT1|AV_CH_FRONT_LEFT_OF_CENTER|AV_CH_FRONT_RIGHT_OF_CENTER)
228 #define AV_CH_LAYOUT_7POINT1_WIDE_BACK (AV_CH_LAYOUT_5POINT1_BACK|AV_CH_FRONT_LEFT_OF_CENTER|AV_CH_FRONT_RIGHT_OF_CENTER)
229 #define AV_CH_LAYOUT_OCTAGONAL (AV_CH_LAYOUT_5POINT0|AV_CH_BACK_LEFT|AV_CH_BACK_CENTER|AV_CH_BACK_RIGHT)
230 #define AV_CH_LAYOUT_HEXADECAGONAL (AV_CH_LAYOUT_OCTAGONAL|AV_CH_WIDE_LEFT|AV_CH_WIDE_RIGHT|AV_CH_TOP_BACK_LEFT|AV_CH_TOP_BACK_RIGHT|AV_CH_TOP_BACK_CENTER|AV_CH_TOP_FRONT_CENTER|AV_CH_TOP_FRONT_LEFT|AV_CH_TOP_FRONT_RIGHT)
231 #define AV_CH_LAYOUT_STEREO_DOWNMIX (AV_CH_STEREO_LEFT|AV_CH_STEREO_RIGHT)
232 #define AV_CH_LAYOUT_22POINT2 (AV_CH_LAYOUT_5POINT1_BACK|AV_CH_FRONT_LEFT_OF_CENTER|AV_CH_FRONT_RIGHT_OF_CENTER|AV_CH_BACK_CENTER|AV_CH_LOW_FREQUENCY_2|AV_CH_SIDE_LEFT|AV_CH_SIDE_RIGHT|AV_CH_TOP_FRONT_LEFT|AV_CH_TOP_FRONT_RIGHT|AV_CH_TOP_FRONT_CENTER|AV_CH_TOP_CENTER|AV_CH_TOP_BACK_LEFT|AV_CH_TOP_BACK_RIGHT|AV_CH_TOP_SIDE_LEFT|AV_CH_TOP_SIDE_RIGHT|AV_CH_TOP_BACK_CENTER|AV_CH_BOTTOM_FRONT_CENTER|AV_CH_BOTTOM_FRONT_LEFT|AV_CH_BOTTOM_FRONT_RIGHT)
233 
243 };
244 
245 /**
246  * @}
247  */
248 
249 /**
250  * An AVChannelCustom defines a single channel within a custom order layout
251  *
252  * Unlike most structures in FFmpeg, sizeof(AVChannelCustom) is a part of the
253  * public ABI.
254  *
255  * No new fields may be added to it without a major version bump.
256  */
257 typedef struct AVChannelCustom {
258  enum AVChannel id;
259  char name[16];
260  void *opaque;
262 
263 /**
264  * An AVChannelLayout holds information about the channel layout of audio data.
265  *
266  * A channel layout here is defined as a set of channels ordered in a specific
267  * way (unless the channel order is AV_CHANNEL_ORDER_UNSPEC, in which case an
268  * AVChannelLayout carries only the channel count).
269  *
270  * Unlike most structures in Libav, sizeof(AVChannelLayout) is a part of the
271  * public ABI and may be used by the caller. E.g. it may be allocated on stack
272  * or embedded in caller-defined structs.
273  *
274  * AVChannelLayout can be initialized as follows:
275  * - default initialization with {0}, followed by setting all used fields
276  * correctly;
277  * - by assigning one of the predefined AV_CHANNEL_LAYOUT_* initializers;
278  * - with a constructor function, such as av_channel_layout_default(),
279  * av_channel_layout_from_mask() or av_channel_layout_from_string().
280  *
281  * The channel layout must be unitialized with av_channel_layout_uninit()
282  *
283  * Copying an AVChannelLayout via assigning is forbidden,
284  * av_channel_layout_copy() must be used instead (and its return value should
285  * be checked)
286  *
287  * No new fields may be added to it without a major version bump, except for
288  * new elements of the union fitting in sizeof(uint64_t).
289  */
290 typedef struct AVChannelLayout {
291  /**
292  * Channel order used in this layout.
293  * This is a mandatory field.
294  */
296 
297  /**
298  * Number of channels in this layout. Mandatory field.
299  */
301 
302  /**
303  * Details about which channels are present in this layout.
304  * For AV_CHANNEL_ORDER_UNSPEC, this field is undefined and must not be
305  * used.
306  */
307  union {
308  /**
309  * This member must be used for AV_CHANNEL_ORDER_NATIVE, and may be used
310  * for AV_CHANNEL_ORDER_AMBISONIC to signal non-diegetic channels.
311  * It is a bitmask, where the position of each set bit means that the
312  * AVChannel with the corresponding value is present.
313  *
314  * I.e. when (mask & (1 << AV_CHAN_FOO)) is non-zero, then AV_CHAN_FOO
315  * is present in the layout. Otherwise it is not present.
316  *
317  * @note when a channel layout using a bitmask is constructed or
318  * modified manually (i.e. not using any of the av_channel_layout_*
319  * functions), the code doing it must ensure that the number of set bits
320  * is equal to nb_channels.
321  */
322  uint64_t mask;
323  /**
324  * This member must be used when the channel order is
325  * AV_CHANNEL_ORDER_CUSTOM. It is a nb_channels-sized array, with each
326  * element signalling the presence of the AVChannel with the
327  * corresponding value in map[i].id.
328  *
329  * I.e. when map[i].id is equal to AV_CHAN_FOO, then AV_CH_FOO is the
330  * i-th channel in the audio data.
331  *
332  * When map[i].id is in the range between AV_CHAN_AMBISONIC_BASE and
333  * AV_CHAN_AMBISONIC_END (inclusive), the channel contains an ambisonic
334  * component with ACN index (as defined above)
335  * n = map[i].id - AV_CHAN_AMBISONIC_BASE.
336  *
337  * map[i].name may be filled with a 0-terminated string, in which case
338  * it will be used for the purpose of identifying the channel with the
339  * convenience functions below. Otherise it must be zeroed.
340  */
342  } u;
343 
344  /**
345  * For some private data of the user.
346  */
347  void *opaque;
349 
350 #define AV_CHANNEL_LAYOUT_MASK(nb, m) \
351  { .order = AV_CHANNEL_ORDER_NATIVE, .nb_channels = (nb), .u = { .mask = (m) }}
352 
353 #define AV_CHANNEL_LAYOUT_MONO AV_CHANNEL_LAYOUT_MASK(1, AV_CH_LAYOUT_MONO)
354 #define AV_CHANNEL_LAYOUT_STEREO AV_CHANNEL_LAYOUT_MASK(2, AV_CH_LAYOUT_STEREO)
355 #define AV_CHANNEL_LAYOUT_2POINT1 AV_CHANNEL_LAYOUT_MASK(3, AV_CH_LAYOUT_2POINT1)
356 #define AV_CHANNEL_LAYOUT_2_1 AV_CHANNEL_LAYOUT_MASK(3, AV_CH_LAYOUT_2_1)
357 #define AV_CHANNEL_LAYOUT_SURROUND AV_CHANNEL_LAYOUT_MASK(3, AV_CH_LAYOUT_SURROUND)
358 #define AV_CHANNEL_LAYOUT_3POINT1 AV_CHANNEL_LAYOUT_MASK(4, AV_CH_LAYOUT_3POINT1)
359 #define AV_CHANNEL_LAYOUT_4POINT0 AV_CHANNEL_LAYOUT_MASK(4, AV_CH_LAYOUT_4POINT0)
360 #define AV_CHANNEL_LAYOUT_4POINT1 AV_CHANNEL_LAYOUT_MASK(5, AV_CH_LAYOUT_4POINT1)
361 #define AV_CHANNEL_LAYOUT_2_2 AV_CHANNEL_LAYOUT_MASK(4, AV_CH_LAYOUT_2_2)
362 #define AV_CHANNEL_LAYOUT_QUAD AV_CHANNEL_LAYOUT_MASK(4, AV_CH_LAYOUT_QUAD)
363 #define AV_CHANNEL_LAYOUT_5POINT0 AV_CHANNEL_LAYOUT_MASK(5, AV_CH_LAYOUT_5POINT0)
364 #define AV_CHANNEL_LAYOUT_5POINT1 AV_CHANNEL_LAYOUT_MASK(6, AV_CH_LAYOUT_5POINT1)
365 #define AV_CHANNEL_LAYOUT_5POINT0_BACK AV_CHANNEL_LAYOUT_MASK(5, AV_CH_LAYOUT_5POINT0_BACK)
366 #define AV_CHANNEL_LAYOUT_5POINT1_BACK AV_CHANNEL_LAYOUT_MASK(6, AV_CH_LAYOUT_5POINT1_BACK)
367 #define AV_CHANNEL_LAYOUT_6POINT0 AV_CHANNEL_LAYOUT_MASK(6, AV_CH_LAYOUT_6POINT0)
368 #define AV_CHANNEL_LAYOUT_6POINT0_FRONT AV_CHANNEL_LAYOUT_MASK(6, AV_CH_LAYOUT_6POINT0_FRONT)
369 #define AV_CHANNEL_LAYOUT_HEXAGONAL AV_CHANNEL_LAYOUT_MASK(6, AV_CH_LAYOUT_HEXAGONAL)
370 #define AV_CHANNEL_LAYOUT_6POINT1 AV_CHANNEL_LAYOUT_MASK(7, AV_CH_LAYOUT_6POINT1)
371 #define AV_CHANNEL_LAYOUT_6POINT1_BACK AV_CHANNEL_LAYOUT_MASK(7, AV_CH_LAYOUT_6POINT1_BACK)
372 #define AV_CHANNEL_LAYOUT_6POINT1_FRONT AV_CHANNEL_LAYOUT_MASK(7, AV_CH_LAYOUT_6POINT1_FRONT)
373 #define AV_CHANNEL_LAYOUT_7POINT0 AV_CHANNEL_LAYOUT_MASK(7, AV_CH_LAYOUT_7POINT0)
374 #define AV_CHANNEL_LAYOUT_7POINT0_FRONT AV_CHANNEL_LAYOUT_MASK(7, AV_CH_LAYOUT_7POINT0_FRONT)
375 #define AV_CHANNEL_LAYOUT_7POINT1 AV_CHANNEL_LAYOUT_MASK(8, AV_CH_LAYOUT_7POINT1)
376 #define AV_CHANNEL_LAYOUT_7POINT1_WIDE AV_CHANNEL_LAYOUT_MASK(8, AV_CH_LAYOUT_7POINT1_WIDE)
377 #define AV_CHANNEL_LAYOUT_7POINT1_WIDE_BACK AV_CHANNEL_LAYOUT_MASK(8, AV_CH_LAYOUT_7POINT1_WIDE_BACK)
378 #define AV_CHANNEL_LAYOUT_OCTAGONAL AV_CHANNEL_LAYOUT_MASK(8, AV_CH_LAYOUT_OCTAGONAL)
379 #define AV_CHANNEL_LAYOUT_HEXADECAGONAL AV_CHANNEL_LAYOUT_MASK(16, AV_CH_LAYOUT_HEXADECAGONAL)
380 #define AV_CHANNEL_LAYOUT_STEREO_DOWNMIX AV_CHANNEL_LAYOUT_MASK(2, AV_CH_LAYOUT_STEREO_DOWNMIX)
381 #define AV_CHANNEL_LAYOUT_22POINT2 AV_CHANNEL_LAYOUT_MASK(24, AV_CH_LAYOUT_22POINT2)
382 #define AV_CHANNEL_LAYOUT_AMBISONIC_FIRST_ORDER \
383  { .order = AV_CHANNEL_ORDER_AMBISONIC, .nb_channels = 4, .u = { .mask = 0 }}
384 
385 struct AVBPrint;
386 
387 #if FF_API_OLD_CHANNEL_LAYOUT
388 /**
389  * Return a channel layout id that matches name, or 0 if no match is found.
390  *
391  * name can be one or several of the following notations,
392  * separated by '+' or '|':
393  * - the name of an usual channel layout (mono, stereo, 4.0, quad, 5.0,
394  * 5.0(side), 5.1, 5.1(side), 7.1, 7.1(wide), downmix);
395  * - the name of a single channel (FL, FR, FC, LFE, BL, BR, FLC, FRC, BC,
396  * SL, SR, TC, TFL, TFC, TFR, TBL, TBC, TBR, DL, DR);
397  * - a number of channels, in decimal, followed by 'c', yielding
398  * the default channel layout for that number of channels (@see
399  * av_get_default_channel_layout);
400  * - a channel layout mask, in hexadecimal starting with "0x" (see the
401  * AV_CH_* macros).
402  *
403  * Example: "stereo+FC" = "2c+FC" = "2c+1c" = "0x7"
404  *
405  * @deprecated use av_channel_layout_from_string()
406  */
408 uint64_t av_get_channel_layout(const char *name);
409 
410 /**
411  * Return a channel layout and the number of channels based on the specified name.
412  *
413  * This function is similar to (@see av_get_channel_layout), but can also parse
414  * unknown channel layout specifications.
415  *
416  * @param[in] name channel layout specification string
417  * @param[out] channel_layout parsed channel layout (0 if unknown)
418  * @param[out] nb_channels number of channels
419  *
420  * @return 0 on success, AVERROR(EINVAL) if the parsing fails.
421  * @deprecated use av_channel_layout_from_string()
422  */
424 int av_get_extended_channel_layout(const char *name, uint64_t* channel_layout, int* nb_channels);
425 
426 /**
427  * Return a description of a channel layout.
428  * If nb_channels is <= 0, it is guessed from the channel_layout.
429  *
430  * @param buf put here the string containing the channel layout
431  * @param buf_size size in bytes of the buffer
432  * @deprecated use av_channel_layout_describe()
433  */
435 void av_get_channel_layout_string(char *buf, int buf_size, int nb_channels, uint64_t channel_layout);
436 
437 /**
438  * Append a description of a channel layout to a bprint buffer.
439  * @deprecated use av_channel_layout_describe()
440  */
442 void av_bprint_channel_layout(struct AVBPrint *bp, int nb_channels, uint64_t channel_layout);
443 
444 /**
445  * Return the number of channels in the channel layout.
446  * @deprecated use AVChannelLayout.nb_channels
447  */
449 int av_get_channel_layout_nb_channels(uint64_t channel_layout);
450 
451 /**
452  * Return default channel layout for a given number of channels.
453  *
454  * @deprecated use av_channel_layout_default()
455  */
457 int64_t av_get_default_channel_layout(int nb_channels);
458 
459 /**
460  * Get the index of a channel in channel_layout.
461  *
462  * @param channel a channel layout describing exactly one channel which must be
463  * present in channel_layout.
464  *
465  * @return index of channel in channel_layout on success, a negative AVERROR
466  * on error.
467  *
468  * @deprecated use av_channel_layout_index_from_channel()
469  */
471 int av_get_channel_layout_channel_index(uint64_t channel_layout,
472  uint64_t channel);
473 
474 /**
475  * Get the channel with the given index in channel_layout.
476  * @deprecated use av_channel_layout_channel_from_index()
477  */
479 uint64_t av_channel_layout_extract_channel(uint64_t channel_layout, int index);
480 
481 /**
482  * Get the name of a given channel.
483  *
484  * @return channel name on success, NULL on error.
485  *
486  * @deprecated use av_channel_name()
487  */
489 const char *av_get_channel_name(uint64_t channel);
490 
491 /**
492  * Get the description of a given channel.
493  *
494  * @param channel a channel layout with a single channel
495  * @return channel description on success, NULL on error
496  * @deprecated use av_channel_description()
497  */
499 const char *av_get_channel_description(uint64_t channel);
500 
501 /**
502  * Get the value and name of a standard channel layout.
503  *
504  * @param[in] index index in an internal list, starting at 0
505  * @param[out] layout channel layout mask
506  * @param[out] name name of the layout
507  * @return 0 if the layout exists,
508  * <0 if index is beyond the limits
509  * @deprecated use av_channel_layout_standard()
510  */
512 int av_get_standard_channel_layout(unsigned index, uint64_t *layout,
513  const char **name);
514 #endif
515 
516 /**
517  * Get a human readable string in an abbreviated form describing a given channel.
518  * This is the inverse function of @ref av_channel_from_string().
519  *
520  * @param buf pre-allocated buffer where to put the generated string
521  * @param buf_size size in bytes of the buffer.
522  * @return amount of bytes needed to hold the output string, or a negative AVERROR
523  * on failure. If the returned value is bigger than buf_size, then the
524  * string was truncated.
525  */
526 int av_channel_name(char *buf, size_t buf_size, enum AVChannel channel);
527 
528 /**
529  * bprint variant of av_channel_name().
530  *
531  * @note the string will be appended to the bprint buffer.
532  */
533 void av_channel_name_bprint(struct AVBPrint *bp, enum AVChannel channel_id);
534 
535 /**
536  * Get a human readable string describing a given channel.
537  *
538  * @param buf pre-allocated buffer where to put the generated string
539  * @param buf_size size in bytes of the buffer.
540  * @return amount of bytes needed to hold the output string, or a negative AVERROR
541  * on failure. If the returned value is bigger than buf_size, then the
542  * string was truncated.
543  */
544 int av_channel_description(char *buf, size_t buf_size, enum AVChannel channel);
545 
546 /**
547  * bprint variant of av_channel_description().
548  *
549  * @note the string will be appended to the bprint buffer.
550  */
551 void av_channel_description_bprint(struct AVBPrint *bp, enum AVChannel channel_id);
552 
553 /**
554  * This is the inverse function of @ref av_channel_name().
555  *
556  * @return the channel with the given name
557  * AV_CHAN_NONE when name does not identify a known channel
558  */
559 enum AVChannel av_channel_from_string(const char *name);
560 
561 /**
562  * Initialize a native channel layout from a bitmask indicating which channels
563  * are present.
564  *
565  * @param channel_layout the layout structure to be initialized
566  * @param mask bitmask describing the channel layout
567  *
568  * @return 0 on success
569  * AVERROR(EINVAL) for invalid mask values
570  */
571 int av_channel_layout_from_mask(AVChannelLayout *channel_layout, uint64_t mask);
572 
573 /**
574  * Initialize a channel layout from a given string description.
575  * The input string can be represented by:
576  * - the formal channel layout name (returned by av_channel_layout_describe())
577  * - single or multiple channel names (returned by av_channel_name(), eg. "FL",
578  * or concatenated with "+", each optionally containing a custom name after
579  * a "@", eg. "FL@Left+FR@Right+LFE")
580  * - a decimal or hexadecimal value of a native channel layout (eg. "4" or "0x4")
581  * - the number of channels with default layout (eg. "4c")
582  * - the number of unordered channels (eg. "4C" or "4 channels")
583  * - the ambisonic order followed by optional non-diegetic channels (eg.
584  * "ambisonic 2+stereo")
585  *
586  * @param channel_layout input channel layout
587  * @param str string describing the channel layout
588  * @return 0 channel layout was detected, AVERROR_INVALIDATATA otherwise
589  */
591  const char *str);
592 
593 /**
594  * Get the default channel layout for a given number of channels.
595  *
596  * @param channel_layout the layout structure to be initialized
597  * @param nb_channels number of channels
598  */
599 void av_channel_layout_default(AVChannelLayout *ch_layout, int nb_channels);
600 
601 /**
602  * Iterate over all standard channel layouts.
603  *
604  * @param opaque a pointer where libavutil will store the iteration state. Must
605  * point to NULL to start the iteration.
606  *
607  * @return the standard channel layout or NULL when the iteration is
608  * finished
609  */
610 const AVChannelLayout *av_channel_layout_standard(void **opaque);
611 
612 /**
613  * Free any allocated data in the channel layout and reset the channel
614  * count to 0.
615  *
616  * @param channel_layout the layout structure to be uninitialized
617  */
618 void av_channel_layout_uninit(AVChannelLayout *channel_layout);
619 
620 /**
621  * Make a copy of a channel layout. This differs from just assigning src to dst
622  * in that it allocates and copies the map for AV_CHANNEL_ORDER_CUSTOM.
623  *
624  * @note the destination channel_layout will be always uninitialized before copy.
625  *
626  * @param dst destination channel layout
627  * @param src source channel layout
628  * @return 0 on success, a negative AVERROR on error.
629  */
631 
632 /**
633  * Get a human-readable string describing the channel layout properties.
634  * The string will be in the same format that is accepted by
635  * @ref av_channel_layout_from_string(), allowing to rebuild the same
636  * channel layout, except for opaque pointers.
637  *
638  * @param channel_layout channel layout to be described
639  * @param buf pre-allocated buffer where to put the generated string
640  * @param buf_size size in bytes of the buffer.
641  * @return amount of bytes needed to hold the output string, or a negative AVERROR
642  * on failure. If the returned value is bigger than buf_size, then the
643  * string was truncated.
644  */
645 int av_channel_layout_describe(const AVChannelLayout *channel_layout,
646  char *buf, size_t buf_size);
647 
648 /**
649  * bprint variant of av_channel_layout_describe().
650  *
651  * @note the string will be appended to the bprint buffer.
652  * @return 0 on success, or a negative AVERROR value on failure.
653  */
654 int av_channel_layout_describe_bprint(const AVChannelLayout *channel_layout,
655  struct AVBPrint *bp);
656 
657 /**
658  * Get the channel with the given index in a channel layout.
659  *
660  * @param channel_layout input channel layout
661  * @return channel with the index idx in channel_layout on success or
662  * AV_CHAN_NONE on failure (if idx is not valid or the channel order is
663  * unspecified)
664  */
665 enum AVChannel
666 av_channel_layout_channel_from_index(const AVChannelLayout *channel_layout, unsigned int idx);
667 
668 /**
669  * Get the index of a given channel in a channel layout. In case multiple
670  * channels are found, only the first match will be returned.
671  *
672  * @param channel_layout input channel layout
673  * @return index of channel in channel_layout on success or a negative number if
674  * channel is not present in channel_layout.
675  */
676 int av_channel_layout_index_from_channel(const AVChannelLayout *channel_layout,
677  enum AVChannel channel);
678 
679 /**
680  * Get the index in a channel layout of a channel described by the given string.
681  * In case multiple channels are found, only the first match will be returned.
682  *
683  * This function accepts channel names in the same format as
684  * @ref av_channel_from_string().
685  *
686  * @param channel_layout input channel layout
687  * @return a channel index described by the given string, or a negative AVERROR
688  * value.
689  */
690 int av_channel_layout_index_from_string(const AVChannelLayout *channel_layout,
691  const char *name);
692 
693 /**
694  * Get a channel described by the given string.
695  *
696  * This function accepts channel names in the same format as
697  * @ref av_channel_from_string().
698  *
699  * @param channel_layout input channel layout
700  * @return a channel described by the given string in channel_layout on success
701  * or AV_CHAN_NONE on failure (if the string is not valid or the channel
702  * order is unspecified)
703  */
704 enum AVChannel
706  const char *name);
707 
708 /**
709  * Find out what channels from a given set are present in a channel layout,
710  * without regard for their positions.
711  *
712  * @param channel_layout input channel layout
713  * @param mask a combination of AV_CH_* representing a set of channels
714  * @return a bitfield representing all the channels from mask that are present
715  * in channel_layout
716  */
717 uint64_t av_channel_layout_subset(const AVChannelLayout *channel_layout,
718  uint64_t mask);
719 
720 /**
721  * Check whether a channel layout is valid, i.e. can possibly describe audio
722  * data.
723  *
724  * @param channel_layout input channel layout
725  * @return 1 if channel_layout is valid, 0 otherwise.
726  */
727 int av_channel_layout_check(const AVChannelLayout *channel_layout);
728 
729 /**
730  * Check whether two channel layouts are semantically the same, i.e. the same
731  * channels are present on the same positions in both.
732  *
733  * If one of the channel layouts is AV_CHANNEL_ORDER_UNSPEC, while the other is
734  * not, they are considered to be unequal. If both are AV_CHANNEL_ORDER_UNSPEC,
735  * they are considered equal iff the channel counts are the same in both.
736  *
737  * @param chl input channel layout
738  * @param chl1 input channel layout
739  * @return 0 if chl and chl1 are equal, 1 if they are not equal. A negative
740  * AVERROR code if one or both are invalid.
741  */
742 int av_channel_layout_compare(const AVChannelLayout *chl, const AVChannelLayout *chl1);
743 
744 /**
745  * @}
746  * @}
747  */
748 
749 #endif /* AVUTIL_CHANNEL_LAYOUT_H */
AV_CHAN_BACK_RIGHT
@ AV_CHAN_BACK_RIGHT
Definition: channel_layout.h:49
av_get_channel_layout_string
attribute_deprecated void av_get_channel_layout_string(char *buf, int buf_size, int nb_channels, uint64_t channel_layout)
Return a description of a channel layout.
Definition: channel_layout.c:309
av_channel_layout_channel_from_string
enum AVChannel av_channel_layout_channel_from_string(const AVChannelLayout *channel_layout, const char *name)
Get a channel described by the given string.
Definition: channel_layout.c:823
name
it s the only field you need to keep assuming you have a context There is some magic you don t need to care about around this just let it vf default minimum maximum flags name is the option name
Definition: writing_filters.txt:88
AV_CHAN_STEREO_RIGHT
@ AV_CHAN_STEREO_RIGHT
See above.
Definition: channel_layout.h:65
AV_CHAN_TOP_FRONT_LEFT
@ AV_CHAN_TOP_FRONT_LEFT
Definition: channel_layout.h:56
AV_CHAN_LOW_FREQUENCY_2
@ AV_CHAN_LOW_FREQUENCY_2
Definition: channel_layout.h:70
AV_CHAN_TOP_BACK_LEFT
@ AV_CHAN_TOP_BACK_LEFT
Definition: channel_layout.h:59
av_get_channel_layout
attribute_deprecated uint64_t av_get_channel_layout(const char *name)
Return a channel layout id that matches name, or 0 if no match is found.
Definition: channel_layout.c:237
AV_CHAN_NONE
@ AV_CHAN_NONE
Invalid channel index.
Definition: channel_layout.h:43
AVChannelLayout::map
AVChannelCustom * map
This member must be used when the channel order is AV_CHANNEL_ORDER_CUSTOM.
Definition: channel_layout.h:341
av_get_default_channel_layout
attribute_deprecated int64_t av_get_default_channel_layout(int nb_channels)
Return default channel layout for a given number of channels.
Definition: channel_layout.c:323
AV_CHAN_LOW_FREQUENCY
@ AV_CHAN_LOW_FREQUENCY
Definition: channel_layout.h:47
av_channel_layout_subset
uint64_t av_channel_layout_subset(const AVChannelLayout *channel_layout, uint64_t mask)
Find out what channels from a given set are present in a channel layout, without regard for their pos...
Definition: channel_layout.c:986
AVChannelLayout::order
enum AVChannelOrder order
Channel order used in this layout.
Definition: channel_layout.h:295
AVChannelLayout::mask
uint64_t mask
This member must be used for AV_CHANNEL_ORDER_NATIVE, and may be used for AV_CHANNEL_ORDER_AMBISONIC ...
Definition: channel_layout.h:322
AVChannelLayout::nb_channels
int nb_channels
Number of channels in this layout.
Definition: channel_layout.h:300
AV_CHAN_BOTTOM_FRONT_LEFT
@ AV_CHAN_BOTTOM_FRONT_LEFT
Definition: channel_layout.h:74
av_channel_layout_copy
int av_channel_layout_copy(AVChannelLayout *dst, const AVChannelLayout *src)
Make a copy of a channel layout.
Definition: channel_layout.c:637
av_get_channel_layout_channel_index
attribute_deprecated int av_get_channel_layout_channel_index(uint64_t channel_layout, uint64_t channel)
Get the index of a channel in channel_layout.
Definition: channel_layout.c:331
AV_CHAN_TOP_BACK_RIGHT
@ AV_CHAN_TOP_BACK_RIGHT
Definition: channel_layout.h:61
AVChannelOrder
AVChannelOrder
Definition: channel_layout.h:101
AVChannel
AVChannel
Definition: channel_layout.h:41
AV_CHAN_STEREO_LEFT
@ AV_CHAN_STEREO_LEFT
Stereo downmix.
Definition: channel_layout.h:63
AV_CHAN_FRONT_RIGHT_OF_CENTER
@ AV_CHAN_FRONT_RIGHT_OF_CENTER
Definition: channel_layout.h:51
AV_CHAN_TOP_FRONT_RIGHT
@ AV_CHAN_TOP_FRONT_RIGHT
Definition: channel_layout.h:58
AV_CHAN_AMBISONIC_END
@ AV_CHAN_AMBISONIC_END
Definition: channel_layout.h:98
av_channel_layout_describe_bprint
int av_channel_layout_describe_bprint(const AVChannelLayout *channel_layout, struct AVBPrint *bp)
bprint variant of av_channel_layout_describe().
Definition: channel_layout.c:730
AV_MATRIX_ENCODING_DOLBY
@ AV_MATRIX_ENCODING_DOLBY
Definition: channel_layout.h:236
AV_CHANNEL_ORDER_NATIVE
@ AV_CHANNEL_ORDER_NATIVE
The native channel order, i.e.
Definition: channel_layout.h:112
mask
static const uint16_t mask[17]
Definition: lzw.c:38
AV_CHAN_FRONT_RIGHT
@ AV_CHAN_FRONT_RIGHT
Definition: channel_layout.h:45
AV_CHANNEL_ORDER_AMBISONIC
@ AV_CHANNEL_ORDER_AMBISONIC
The audio is represented as the decomposition of the sound field into spherical harmonics.
Definition: channel_layout.h:142
AVChannelCustom
An AVChannelCustom defines a single channel within a custom order layout.
Definition: channel_layout.h:257
AV_MATRIX_ENCODING_NB
@ AV_MATRIX_ENCODING_NB
Definition: channel_layout.h:242
AV_CHANNEL_ORDER_UNSPEC
@ AV_CHANNEL_ORDER_UNSPEC
Only the channel count is specified, without any further information about the channel order.
Definition: channel_layout.h:106
AV_MATRIX_ENCODING_DPLIIX
@ AV_MATRIX_ENCODING_DPLIIX
Definition: channel_layout.h:238
AV_CHAN_TOP_BACK_CENTER
@ AV_CHAN_TOP_BACK_CENTER
Definition: channel_layout.h:60
AV_CHAN_BOTTOM_FRONT_CENTER
@ AV_CHAN_BOTTOM_FRONT_CENTER
Definition: channel_layout.h:73
AV_CHAN_TOP_FRONT_CENTER
@ AV_CHAN_TOP_FRONT_CENTER
Definition: channel_layout.h:57
AVMatrixEncoding
AVMatrixEncoding
Definition: channel_layout.h:234
AV_MATRIX_ENCODING_DOLBYHEADPHONE
@ AV_MATRIX_ENCODING_DOLBYHEADPHONE
Definition: channel_layout.h:241
AVChannelLayout::u
union AVChannelLayout::@303 u
Details about which channels are present in this layout.
AV_CHAN_AMBISONIC_BASE
@ AV_CHAN_AMBISONIC_BASE
Range of channels between AV_CHAN_AMBISONIC_BASE and AV_CHAN_AMBISONIC_END represent Ambisonic compon...
Definition: channel_layout.h:95
AV_CHANNEL_ORDER_CUSTOM
@ AV_CHANNEL_ORDER_CUSTOM
The channel order does not correspond to any other predefined order and is stored as an explicit map.
Definition: channel_layout.h:119
AV_CHAN_FRONT_LEFT
@ AV_CHAN_FRONT_LEFT
Definition: channel_layout.h:44
av_channel_layout_compare
int av_channel_layout_compare(const AVChannelLayout *chl, const AVChannelLayout *chl1)
Check whether two channel layouts are semantically the same, i.e.
Definition: channel_layout.c:930
AV_CHAN_UNKNOWN
@ AV_CHAN_UNKNOWN
Channel contains data, but its position is unknown.
Definition: channel_layout.h:81
av_channel_layout_default
void av_channel_layout_default(AVChannelLayout *ch_layout, int nb_channels)
Get the default channel layout for a given number of channels.
Definition: channel_layout.c:960
AV_CHAN_FRONT_LEFT_OF_CENTER
@ AV_CHAN_FRONT_LEFT_OF_CENTER
Definition: channel_layout.h:50
av_get_channel_name
const attribute_deprecated char * av_get_channel_name(uint64_t channel)
Get the name of a given channel.
Definition: channel_layout.c:341
index
int index
Definition: gxfenc.c:89
av_channel_layout_uninit
void av_channel_layout_uninit(AVChannelLayout *channel_layout)
Free any allocated data in the channel layout and reset the channel count to 0.
Definition: channel_layout.c:630
av_bprint_channel_layout
attribute_deprecated void av_bprint_channel_layout(struct AVBPrint *bp, int nb_channels, uint64_t channel_layout)
Append a description of a channel layout to a bprint buffer.
Definition: channel_layout.c:275
AV_CHAN_TOP_SIDE_RIGHT
@ AV_CHAN_TOP_SIDE_RIGHT
Definition: channel_layout.h:72
AV_CHAN_SIDE_RIGHT
@ AV_CHAN_SIDE_RIGHT
Definition: channel_layout.h:54
AV_CHAN_UNUSED
@ AV_CHAN_UNUSED
Channel is empty can be safely skipped.
Definition: channel_layout.h:78
AV_CHAN_BACK_LEFT
@ AV_CHAN_BACK_LEFT
Definition: channel_layout.h:48
AVChannelLayout
An AVChannelLayout holds information about the channel layout of audio data.
Definition: channel_layout.h:290
av_get_channel_layout_nb_channels
attribute_deprecated int av_get_channel_layout_nb_channels(uint64_t channel_layout)
Return the number of channels in the channel layout.
Definition: channel_layout.c:318
AV_MATRIX_ENCODING_NONE
@ AV_MATRIX_ENCODING_NONE
Definition: channel_layout.h:235
av_channel_from_string
enum AVChannel av_channel_from_string(const char *name)
This is the inverse function of av_channel_name().
Definition: channel_layout.c:141
AV_CHAN_BACK_CENTER
@ AV_CHAN_BACK_CENTER
Definition: channel_layout.h:52
av_get_extended_channel_layout
attribute_deprecated int av_get_extended_channel_layout(const char *name, uint64_t *channel_layout, int *nb_channels)
Return a channel layout and the number of channels based on the specified name.
Definition: channel_layout.c:253
AV_CHAN_WIDE_LEFT
@ AV_CHAN_WIDE_LEFT
Definition: channel_layout.h:66
attribute_deprecated
#define attribute_deprecated
Definition: attributes.h:104
av_get_channel_description
const attribute_deprecated char * av_get_channel_description(uint64_t channel)
Get the description of a given channel.
Definition: channel_layout.c:352
AV_CHAN_SIDE_LEFT
@ AV_CHAN_SIDE_LEFT
Definition: channel_layout.h:53
attributes.h
av_channel_layout_standard
const AVChannelLayout * av_channel_layout_standard(void **opaque)
Iterate over all standard channel layouts.
Definition: channel_layout.c:973
AV_CHAN_TOP_SIDE_LEFT
@ AV_CHAN_TOP_SIDE_LEFT
Definition: channel_layout.h:71
av_channel_name
int av_channel_name(char *buf, size_t buf_size, enum AVChannel channel)
Get a human readable string in an abbreviated form describing a given channel.
Definition: channel_layout.c:101
layout
Filter the word “frame” indicates either a video frame or a group of audio as stored in an AVFrame structure Format for each input and each output the list of supported formats For video that means pixel format For audio that means channel layout
Definition: filter_design.txt:18
av_channel_layout_check
int av_channel_layout_check(const AVChannelLayout *channel_layout)
Check whether a channel layout is valid, i.e.
Definition: channel_layout.c:904
AV_CHAN_FRONT_CENTER
@ AV_CHAN_FRONT_CENTER
Definition: channel_layout.h:46
AVChannelCustom::name
char name[16]
Definition: channel_layout.h:259
av_channel_layout_index_from_channel
int av_channel_layout_index_from_channel(const AVChannelLayout *channel_layout, enum AVChannel channel)
Get the index of a given channel in a channel layout.
Definition: channel_layout.c:834
av_channel_layout_channel_from_index
enum AVChannel av_channel_layout_channel_from_index(const AVChannelLayout *channel_layout, unsigned int idx)
Get the channel with the given index in a channel layout.
Definition: channel_layout.c:794
version.h
av_channel_layout_from_mask
int av_channel_layout_from_mask(AVChannelLayout *channel_layout, uint64_t mask)
Initialize a native channel layout from a bitmask indicating which channels are present.
Definition: channel_layout.c:389
AV_CHAN_SURROUND_DIRECT_RIGHT
@ AV_CHAN_SURROUND_DIRECT_RIGHT
Definition: channel_layout.h:69
AV_CHAN_WIDE_RIGHT
@ AV_CHAN_WIDE_RIGHT
Definition: channel_layout.h:67
AVChannelCustom::opaque
void * opaque
Definition: channel_layout.h:260
AVChannelLayout::opaque
void * opaque
For some private data of the user.
Definition: channel_layout.h:347
AV_MATRIX_ENCODING_DOLBYEX
@ AV_MATRIX_ENCODING_DOLBYEX
Definition: channel_layout.h:240
av_channel_layout_from_string
int av_channel_layout_from_string(AVChannelLayout *channel_layout, const char *str)
Initialize a channel layout from a given string description.
Definition: channel_layout.c:402
av_channel_layout_describe
int av_channel_layout_describe(const AVChannelLayout *channel_layout, char *buf, size_t buf_size)
Get a human-readable string describing the channel layout properties.
Definition: channel_layout.c:776
av_channel_description
int av_channel_description(char *buf, size_t buf_size, enum AVChannel channel)
Get a human readable string describing a given channel.
Definition: channel_layout.c:128
AV_CHAN_SURROUND_DIRECT_LEFT
@ AV_CHAN_SURROUND_DIRECT_LEFT
Definition: channel_layout.h:68
AV_CHAN_BOTTOM_FRONT_RIGHT
@ AV_CHAN_BOTTOM_FRONT_RIGHT
Definition: channel_layout.h:75
src
INIT_CLIP pixel * src
Definition: h264pred_template.c:418
AV_MATRIX_ENCODING_DPLIIZ
@ AV_MATRIX_ENCODING_DPLIIZ
Definition: channel_layout.h:239
convert_header.str
string str
Definition: convert_header.py:20
av_channel_name_bprint
void av_channel_name_bprint(struct AVBPrint *bp, enum AVChannel channel_id)
bprint variant of av_channel_name().
Definition: channel_layout.c:87
av_get_standard_channel_layout
attribute_deprecated int av_get_standard_channel_layout(unsigned index, uint64_t *layout, const char **name)
Get the value and name of a standard channel layout.
Definition: channel_layout.c:377
av_channel_description_bprint
void av_channel_description_bprint(struct AVBPrint *bp, enum AVChannel channel_id)
bprint variant of av_channel_description().
Definition: channel_layout.c:114
AV_CHAN_TOP_CENTER
@ AV_CHAN_TOP_CENTER
Definition: channel_layout.h:55
AVChannelCustom::id
enum AVChannel id
Definition: channel_layout.h:258
av_channel_layout_extract_channel
attribute_deprecated uint64_t av_channel_layout_extract_channel(uint64_t channel_layout, int index)
Get the channel with the given index in channel_layout.
Definition: channel_layout.c:363
channel
channel
Definition: ebur128.h:39
AV_MATRIX_ENCODING_DPLII
@ AV_MATRIX_ENCODING_DPLII
Definition: channel_layout.h:237
av_channel_layout_index_from_string
int av_channel_layout_index_from_string(const AVChannelLayout *channel_layout, const char *name)
Get the index in a channel layout of a channel described by the given string.
Definition: channel_layout.c:868